• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

jacked 5.0 brakes

  • Thread starter Thread starter mynephratieri
  • Start date Start date Jan 29, 2007
M

mynephratieri

New Member
Dec 12, 2006
19
0
0
Jan 29, 2007
#1
  • Jan 29, 2007
  • #1
help! my brakes are rock solid and dont want to stop.new pads,swapped calipers from another car,slotted new rotors,swapped the master cylinder and brake booster and no change.i can slam on them and barely stop.i had a shop do a rear brake job also.yes has all been bled as well.it still is just as hard to stop as before all changes.also the e brake can be yanked at any speed with no results,just the brake light.what is up????????
 

Mustang78

New Member
Feb 8, 2006
486
0
0
Aberdeen, WA
Jan 29, 2007
#2
  • Jan 29, 2007
  • #2
sounds like the rear brakes are out of adjustment, pull the hubs off and you'll see the clicker at the bottom, turn that and test fit the hub again, if it drags slightly it's ok, thats properly adjusted, or so

~Mark~
 

Roland69

Sergeant Tangnet
Sep 17, 2005
2,867
2
58
Port Elgin, Ontario
Jan 29, 2007
#3
  • Jan 29, 2007
  • #3
you can just remove the little rubber plug on the inner side of the backing plate and adjust the rear brakes that way...you want it to just slightly have drag and an even amount on both sides. But as for your question I would lean towards a Vacuum problem perhaps...I have stock brakes and can lock them up kind of easy
 
M

mynephratieri

New Member
Dec 12, 2006
19
0
0
Jan 30, 2007
#4
  • Jan 30, 2007
  • #4
the only vacumm goes to the booster to the intake right?i will try the adjustment part today and see if it changes anything.is there any other vac lines i should check?thanx
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Jan 30, 2007
#5
  • Jan 30, 2007
  • #5
Check the rubber grommet for that brake booster check valve mounts in. It is a known source of leaks. The check valve is the metal fitting on the vacuum line that comes from the vacuum distribution block.

Diagram courtesy of Tmoss & Stang&2birds


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Computer,. actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
 
M

mynephratieri

New Member
Dec 12, 2006
19
0
0
Jan 30, 2007
#6
  • Jan 30, 2007
  • #6
ok,the vac line is all good.the e brake cables are rusted to not moving.i got one broke free, working on the other.i tried the adjustment thing on both sides.totally loose ,then tighter then dragging,then full tight.nothing changed except when full tight,did not spin at all,obviously.tried driving all three times as well as spinning the tire.at 45 mph,the front can lock but not the rear.but the pedal is still so hard not even funny.my 90 vert and 91 gt both are very touchy lock up right.i swapped all components other than the lines themselves,no dice.could the ebrake lines have something to do with this?this sucks!thanx for the reponses guys,appreciate it.
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Jan 30, 2007
#7
  • Jan 30, 2007
  • #7
Power brake booster test:
1.) Check engine vacuum you should have 14"-18" of vacuum at 625-750 RPM, 18"-21" vacuum at 1000 RPM.
2.) Vacuum checks good, start car and run engine up to 1000 RPM for 30 seconds.
3.) Cut off the engine and then press the brake pedal 3 times. It should get harder to press and travel less each time you press it. If it doesn't, then the brake booster is suspect.
 
M

mynephratieri

New Member
Dec 12, 2006
19
0
0
Jan 31, 2007
#8
  • Jan 31, 2007
  • #8
the vac is good,the pedal gets harder.i also swapped the booster from my 90 vert with this one and no change to either vehicle.the booster was what the book said it could be but worked fine in the other vehicle.also when i pull off the vac line the engine wants to die so it is all good there also.crazy huh?
 
M

mynephratieri

New Member
Dec 12, 2006
19
0
0
Feb 4, 2007
#9
  • Feb 4, 2007
  • #9
ok,i rebled the system again,then put the rear on stands.started the car put in drive and ran it up to 35 mph while on the jack stands.i hit the brakes.my rear wheels barely slowed down!the ebrake did not do anything either.so i obviously got a problem in the rear.the rears are getting fluid,when i bled no problem,and after adjusting the rear, hard to get the drum off ,so i know the adjuster works that way.any other ideas?
 
You must log in or register to reply here.

Similar threads

Brakes FOX BRAKES ISSUES
  • PonyGTrider
  • Jan 11, 2026
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
53
Views
2K
Fox 5.0 Mustang Tech Jan 31, 2026
Mustang5L5
8
87 lx 4cyl to v8 project 4 lug disc conversion questions
  • 87lx428
  • Mar 24, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
2
Views
489
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Mar 25, 2026
87lx428
8
Brakes How do I get the e brake cable onto the disc brake caliper??
  • AnthonyA1234
  • May 2, 2025
  • Fox 5.0 Mustang Tech
Replies
8
Views
404
Fox 5.0 Mustang Tech May 2, 2025
AnthonyA1234
D
Brakes 88 LX 5.0 - help! no brakes
  • DRGunn427
  • Feb 26, 2025
  • Fox 5.0 Mustang Tech
Replies
4
Views
405
Fox 5.0 Mustang Tech Feb 27, 2025
nickyb
A
Resolved Brake light switch
  • Alabama
  • Feb 24, 2025
  • Fox 5.0 Mustang Tech
  • 2
Replies
31
Views
3K
Fox 5.0 Mustang Tech Jun 25, 2026
General karthief
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?